Manually actuated jack hammer

ABSTRACT

A manually actuated jack hammer useful as an anchor or post driver, a compactor, a pavement breaker and the like, composed of telescoped ram and barrel members, a recoil spring and a handle which when manually reciprocated will drive the ram and through the recoil action of the spring establish a systematic rhythm causing repeated impact blows with minimum applied manual energy. For low level usage such as for driving anchors into the ground, for compacting the ground or for breaking concrete, the barrel may have the driver head on the end thereof, the ram may be solid entering the open top of the barrel and impacting against the driver, the handle may be attached to the top of the ram and the recoil spring may be compressed between the top of the barrel and the top of the ram. For high level usage such as driving fence posts into the ground, the barrel may be hollow receiving the post therein, the ram may overlie the barrel with the handle attached thereto at a convenient operating level, and the recoil spring may be interposed between the top of the barrel and the top of the ram. The handle is preferably H-shaped with handle grips at the tops and bottoms of the vertical legs. Attachments may be provided to lock the barrel to the anchor, breaker tool or the like and for guiding a fence post in the hollow barrel.

Willie States atent I [191 i Deike 1 Ma 29 1973 [5 4] MANUALLY ACTUATED JACK [57] ABSTRACT HAMMER A manually actuated jack hammer useful as an anchor [75] Inventor: Robert F. Deike, Cheyenne, Wyo. or post driver, a compactor, a pavement breaker and [731 Assignees: William H. Chamberlain; Anna B. 9 fi 1 bafrelmem' I Chamberlain Cheyenne y ers, a recoi spring an I a and e WhlCh when t v E h manually reclprocated Wlll drive the ram and through panm erest. o eac the recoil action of the spring establish a systematic [22] Filed: Mar. 12, 1971 rhythm causing repeated impact blows with minimum applied manual energy. For low level usage such as for [.21] Appl' 123,787 driving anchors into the ground, for compacting the v ground or for breaking concrete, the barrel may have 521 Us 01; ..173/118, 173/91, 173/126 e driverhead Oh the end thereof, the yh [51] llnt. Cl. ..B25d l/00 sohfi emermg open top of the barrel lmpactmg 58 Field ofsearch ..173/91, 128-133, i 3 dmer g s fi h atmhe: the

173 126, 119-121,11s;294 s7,5s;30 277 6 e sprmg may 6 I pressed between the top of the barrel and the top of i 1 the ram. For high level usage such as driving fence References cited posts into the ground, the barrel may be hollow UNITED STATES PATENTS receiving the post therein, the ram may overlie the barrel with the handle attached thereto at a con- 2'903932 9/959 l -173/121 venient operating level, and the recoil spring may be 3,313,356 4/1967 clevfnger "173/91 interposed between the top of the barrel and the top 2,602,360 7/1952 Bernmger.... ....l73l/l2 of the ram. The handle is preferably H-shaped with 12/1963 Lmaberyw' ""173/126 handle grips at the tops and bottoms of the vertical Gunn ..l73/12l legs. Attachments may be provided to lock the barrel to the anchor, breaker tool or the like and for guiding a fence post in the hollow barrel.

9 Claims, 11 Drawing Figures PATENTEDW-Y29|973 3.735822 SHEET 1 OF 3 Fig.1 Fig.2 w F Y 20 v I 20 g a H I l M i iii /4 Ill 22 /4 II 22 a 6 28 A INVENTOR.

7 26a. 2056/7 {fie/144s? swag @779; WW/VTTORNEYS MANUALLY ACTUATED JACK HAMMER BACKGROUND OF THE INVENTION Field of the Invention This invention relates to impact or jack hammers of the manually actuated self-energizing type minimizing manual effort for maximum performance. The invention particularly deals with recoil spring equipped appeated hammer blows at exact desired locations and utilizing the recoil action of the delivered blow to raise paratus delivering repeated impact blows of great magnitude with little manual effort.

SUMMARY OF THE INVENTION According to this invention, there is now provided inexpensive impact or jack hammers readily adaptable for many different usages and comfortably manipulated by an operator with little effort. The tools or apparatus of this invention are composed essentially of a ram, a barrel, and a recoil spring. An I-I-shaped handle is secured to the ram and has hand grips at theterminal ends of its vertical legs so that high level operation is comfortably achieved by, grasping the lower grips, while low level operation is comfortably achieved by grasping the upper grips. The tools of this invention are manipulated by an operator standing erect, grasping the hand grips at the most convenient level, and alternately lifting and dropping the ram while guided by the barrel until the recoil spring is brought into action,

. whereupon a rhythmatic alternate lifting and downward thrusting of the operators hands and arms will deliver strong sledge hammer like impact blows to a driving head. Various attachments for tools are provided facilitating their use for different purposes.

In one form the tool has an elongated solid impact ram telescoped through the top of a receiver barrel which has a driver head at the bottom thereof. A compression spring is positioned between the top of the barrel and the top of the ram and a handle is attached to the ram. Lifting and dropping of the ram in the barrel will impact the driver head to deliver blows to an attachment, an anchor or the like. In another form, the ram is hollow receiving a guide barrel with an open bottom receiving a fence post or the like. The ram overlies the upper portion of the barrel, and the handle is attached to the ram to facilitate lifting and dropping of the same for causing adriving head in the ram to strike against the top of the barrel, thereby delivering the impact blows to the fence post or the like telescoped in the barrel. The compression spring is positioned between the top of the ram and the top of the barrel.

The telescoped ram and barrel elements maybe cylindrical, square, or 'may have any desired crosssectional shape preventing relative rotation of the barrel and ram.

The driver head may be fixed to the barrel or may be in the form of a floating head. A second recoil spring can be'provided between the floating head and the barrel or ram to absorb impact recoil between the head and its mounting. If desired, the driving head end of the tool may be attached to the member being driven to prevent separathe hammer for the next blow.

Another object of the invention is to provide a completely guided jack hammer with a recoil spring which assists manual actuation to lessen input energy.

Another object of the invention is to provide an impact tool easily operated from a selected convenient level by a rhythmic raising and lowering action assisted with a recoil spring.

A still further object of this invention is to provide a jack hammer with an H-shaped handle having hand grips at both ends thereof for grasping at a convenient level.

Another object of the invention is to provide a jack hammer with a floating impact head and a recoil spring maintaining the head in contact with the work piece.

Another object of the invention is to provide a jack hammer composed of a ram, a barrel, a recoil spring, and an actuating handle that can be gripped at a convenient level.

Another object of this invention is to provide a post driver having a hollow barrel receiving the post therein, aram telescoped over the top of the barrel, an operating handle on the ram, and a recoil spring between the ram and barrel effective to lift the ram.

A specific object of this invention is to provide a jack hammer with attachments for locking the 'driving'head to the apparatus to be driven.

Other and further objects of the invention will be apparent to those skilledin this art from the following detailed description of the annexed sheets of drawings which, by way of preferred examples, illustrate several embodiments of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view, with parts in elevation, of a jack hammer according to this invention showing the ram in lowered striking position and the leg locks in released position;

FIG. 2 is a view similar to FIG. 1 but showing the ram in its raised position forimpacting and with the leg locks in locked position;

FIG. 3 is a cross-sectional view along the line IIIIII of FIG. 1; 1

FIG. 4 is a-fragmentary side elevational view of the lower portion of the device of FIG. 1 rotated FIG. 5 is a vertical cross-sectional view, with parts in elevation, of a first modified form of the jack hammer of this invention showing the ram in its lowered striking position and an impact tool attached to the barrel;

FIG. 6 is a view similar to FIG. 5 but showing the ram in its raised position for impactingj FIG. 7 is a transverse cross-sectional view taken along the line VIIVII of FIG. 5;

FIG. 8 is a vertical cross-sectional view, with parts in elevation, of a second modified form of the jack hammer of this invention showing a hollow barrel receiving a fence post therein and guiding a hollow ram with the ram in impacting position;

FIG. 9 is a view similar to FIG. 8 but showing the ram in raised position} FIG. 10 is a cross-sectional view taken along the line XX of FIG. 8; and

FIG. 11 is a fragmentary view of another modified form of jack hammer having a floating striking head.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The jack hammer of FIGS. 1 to 4 has an elongated solid metal cylindrical ram 11, of substantial weight, telescoped in a hollow cylindrical metal receiver barrel 12 having a driver head 13 secured on the lower end thereof and an end cap 14 detachably clamped on the open top end thereof with an aperture slidably receiving the ram 11 therethrough. A compression coil spring 15 surrounds the upper portion of the ram 11. An H- shaped handle 16 has a horizontal crossbar 17 rigidly secured to the top end of the ram 11 in any suitable manner, as for example by slotting the top end of the ram as at 18 to receive the bar 17 and securing the bar in the slot as by bolts or rivets 19. The ends of the bar 17 have upright rods 20 secured thereto with portions of each rod extending both above and below the bar. Hand grips 21 are provided on the upper ends of the rods 20 and hand grips 22 are provided on the lower ends of the rods 20.

The top end of the compression spring 15 is secured at 23 to the crossbar 17 and the top end coil of this spring underlies the crossbar in close adjacent relation. The spring 15 thus moves with the ram 11, but the bottom end coil of the spring thrusts against the end cap 14 when the ram is lowered into the barrel.

A second compression coil spring 24 loosely surrounds the lower end of the barrel 12 and is bottomed on the driver head 13. A sleeve 25 slidable on the barrel rests on this spring 24. A handle 26 has a bifurcated end 26a loosely embracing the sleeve 25. Both arms of the end 26a are pivoted to the sleeve at 27. A pair of leg locks or anchor rods 28 are pivotally suspended from the handle 26 in spaced relation from the pivot 27. These legs 28 have inturned free ends 28a adapted to be swung under a work piece such as a ground anchor A to be driven into the ground G by the hammer 10. A typical ground anchor A has a head H and a pointed rod R depending therefrom. The inturned ends 28a of the legs 28 are adapted to be swung under the head H. As illustrated, the anchor A may also have a nipple or lug projecting above the head H and if so, a recess 13a is provided in the driver head to receive this lug so that the driver head will impact against the head H.

When the handle 26 is swung from a lowered position as shown'in FIG. 1 to a raised position as shown in FIG. 2, the legs 28 are raised so that their ends 28a will engage the bottom of the anchor head H, and continued upward swinging of the arm will compress the spring 24 -to lock the anchor tightly against the driver head 13.

The top hand grips 21 are conveniently gripped for actuating the jack hammer 10 when it is at a low level. The bottom hand grips 22 are more conveniently gripped when the head H of the anchor A is considerably above the ground level G.

The jack hammer 10 is actuated by raising the handle 16 to a position such as shown in FIG. 2, thereby lifting the ram 11 a considerable distance above the driving head 13. Then the handle is released to allow the ram to drop and impact against the head 13. Immediately prior to impact the recoil spring 15 will engage the cap 14 so that the spring will be compressed between the end cap 14 and the crossbar 17 of the handle and this compression of the spring imparts a rebound action to the ram after impact assisting the lifting of the ram. The

operator soon picks up the rhythm of the lifting and dropping interval and adds a downward thrust force in increase the impact of the ram against the driver head.

It will be appreciated that the weight of the ram 11, the added manually applied downward thrust and the velocity of the ram movement relative to the barrel will create an effective sledge hammer blow on the driver fully guided by the barrel 12. The recoil spring 15 is compressed during each impact stroke providing a rebound force assisting the raising of the ram for the next impact blow.

Since the anchor A is locked to the driver head 13, no lost motion can occur between impact blows and the hammer will not bounce off of the work piece.

A tamping pad can easily be secured to the bottom of the driving head 13 as by threading a lug on such a pad into the recess 13a. Likewise, a concrete breaking bit could be secured to the driving head for converting the hammer into a compactor or concrete breaking tool.

The modified jack hammer 30 of FIGS. 5 and 6 has a ram 31 of square cross-section telescoped into a barrel 32 also of square configuration. The bottom of the barrel has a driver head 33 secured thereon and the top of the barrel has an end cap 34 detachably clamped thereon. A compression coil spring 35 surrounds the upper portion of the square ram 31 and an H-shaped handle 36 has a horizontal crossbar 37 secured to the upper end of the square ram 31 as by providing a slot 38 in the upper end of the ram receiving the crossbar which is then anchored in position by bolts or rivets 39. The handle 36 has vertical rods 40 secured at the ends of the crossbar l7 and projecting both above and below the crossbar with hand grips 41 on the top ends thereof and hand grips 42 on the bottom ends thereof. The top end of the coil spring 35 is secured to the crossbar 37 as at 43 with the top end coil of the spring positioned closely adjacent the bottom of the crossbar 17 and with the bottom coil of the spring adapted to thrust against the cap 34 when the ram is lowered into the barrel.

The cap 34 has a square hole slidably receiving the square ram 31 therethrough. The lower end of the ram 31 has an enlarged square guidance section 31a slidable in the square barrel 32 and cooperating with the square hole in the cap 34 to maintain the ram 31 in the central portion of the barrel. A second coil spring 44 loosely surrounds the ram 31 between the guidance section 31a and the cap 34 being bottomed on the guidance section 31a and thrusting against the cap 31 when the ram is at the top end of its stroke. This second spring 44 is compressed on the upward stroke creating a downward thrust action to the ram.

The bottom of the square guidance section 310 strikes the driver head 33 at the bottom of the stroke as illustrated in FIG. 5 whereupon the coil spring 35 is compressed adding a recoil force to the ram assisting the next lifting stroke.

The jack hammer 30 operates in the same manner as the hammer 10 with the interfitting square sections of the ram and barrel preventing relative rotation of these telescoping parts.

The driving head 33 on the bottom of the barrel 32 is conveniently clamped against the work piece or the like to be actuated by the jack hammer and for purposes of illustration, a concrete breaking tool bit B has its head H clamped against the bottom 33 of the barrel by means of spring latches 45 pivotally mounted on a sliding plate P on the bit B abutting the head H. The latches have hook ends 46 seated in holes provided in the side wall of the barrel. The latches can be of any convenient spring type or can be in the form of turnbuckles to draw the head H of the tool bit B tightly against the driver head 33 secured to the bottom of the barrel 32.

From the above description it will be understood that the two springs 35 and 44 perform recoil functions assisting the raising and lowering of the ram once the proper rhythm has been established. The spring 35 acts in the same manner as the spring of the jack hammer 10, while the added spring 44 adds to the downward thrust on the impact stroke.

In FIG. 11 a floating driver head arrangement is provided suitable for use with the jack hammers of FIGS. 1 through 7. As shown in FIG. 11, a further modified jack hammer 50 has a cylindrical ram 51 telescoped in a cylindrical barrel 52 and the lower end of the ram has a head 53 secured thereon slidably guiding the ram centrally of the tubular barrel 52. A floating driver head 54 is loosely disposed in the open bottom end of the barrel 52 and has an enlarged top head end 54a, a reduced diameter shank 54b, and an enlarged bottom head 54c. The head 54a is recessed in the top thereof to receive the end of the ram 51.

A collar 55 is secured in the open bottom end of the barrel 52 slidably receiving the stem portion 54b of the driver head 54. The heads 54a and 540 of the driver 54, however, cannot pass through the collar.

A tool bit B with a head H is illustrated as secured directly to the head end 54c of the floating driver head 54. This eliminates the necessity for the spring lock as on the jack hammer 10 or the spring latches as on the jack hammer 30. The free floating driver head reduces frictional resistance, resilience and impact recoil since the impact thrust is imparted independently of the barrel and directly to the work piece.

In the embodiment 60 of FIGS. 8 to 10, an exterior hollow driving ram 61 receives a hollow driven tube 62 through the open bottom thereof. A heavy steel driver head 63 is secured to the upper end of the driving ram 61 as by welding. The hollow tube 62 has a heavy duty plate 64 welded to the top end thereof. A compression spring 65 extends from a recess 66 to the head 63 to be bottomed on the plate 64.

An H-handle assembly 67 has cross rod portions 68 secured in brackets 69 welded to the sides of the exterior driving barrel 61 and has upstanding rod legs 70 at the outer ends of the cross rods 68 with top grips 71 on the upper ends thereof and bottom grips 72 on the lower ends thereof. Bolts 73 extend through the inner .ends of the horizontal rod portions 68 to secure these rod portions to the brackets 69.

In operation the guidance tube 62 is placed over a fence post F.P. with the plate 64 resting on top of the post and with the portion of the post to be driven into the ground projecting below the tube 62. A sleeve 74 having an interior configuration mating with the post configuration is secured in the open bottom end of the tube 62 as by means of wing nuts or the like to guide the fence post F.1P. in the center of the tube.

The jack hammer 60 with the post therein is raised to the desired position for driving the post into the ground and the exterior driving ram 61 is raised and dropped by an operator engaging the lower hand grips 72 of the handle creating a repeating action until the compression of the recoil spring 65 is overcome and the driver barrel head 63 impacts against the end plate or head 64 thereby driving the fence post F.P. into the ground. The guide tube 62 remains stationary with the post RP. and does not move with the driving barrel 61. By adjusting the length of the throw and the speed of the stroke, a desired impact will be developed to drive the post into the ground to its given height. As the post is lowered into the ground, it may become more convenient to engage the upper grips 71 of the I-I-handle 67.

From the above descriptions it will be clear that this invention now provides efficient jack hammers comfortably actuated by an operator and building up a rhythm which delivers sledge hammer like blows to a tool or object to be driven in the ground.

I claim as my invention:

1. A jack hammer comprising telescoped ram and guide barrel members, said barrel member slidably guiding said rarn member for reciprocal movement along an elongated stroke, a driver head at one end of the barrel member having an impact surface, said rarn member having a cooperating impact surface centered by the barrel member to engage said driver head impact surface, said impact surfaces of the ram member and driver head being interior of the telescoped ram and barrel members, an operating handle attached to the ram member adapted to be manually grasped for raising and lowering the ram member relative to the barrel member, and a recoil spring between the members effective to raise the ram member relative to the barrel member after each impact of the respective impact surfaces of the ram and barrel members, said spring having a free extended length substantially less than the stroke of the ram on the barrel to be compressed only at the bottom of the stroke before impact.

2. The jack hammer of claim 1 wherein the ram is telescoped through the open top of the barrel.

3. The jack hammer of claim 1 wherein the ram member is telescoped over the barrel member and the barrel member is hollow with an open bottom, has an anvil head at the top end thereof and receives the workpiece against said head.

4. The jack hammer of claim 1 wherein the operating handle is H-shaped having a crossbar secured to the ram.

5. The jack hammer of claim 1 wherein the barrel has a driving head secured on the bottomthereof.

6. The jack hammer of claim 1 wherein the ram member is a hollow open bottom tube, receives the guide barrel therein in sliding relation therewith along the length thereof and has a driving head secured to the top thereof.

7. A jack hammer which comprises a hollow open bottom guide tube having an anvil secured thereon closing the top end thereof, said guide tube'being of larger diameter than a workpiece to be operated by said jack hammer for receiving the workpiece therein along the length thereof with anvil resting on the top end of the workpiece, a hollow elongated driving ram telescoped over said tube in sliding engagement therewith having a driving head adapted to impact against said anvil on the tube, a compression recoil spring in the hollow driving ram between the anvil and the driving head, said recoil spring having a free end and a free extended length substantially less than the stroke of the driving rarn on the guide tube so as to be compressed only at the bottom of the stroke before the-driving head guide tube receives a fence post therein and a guide member is provided in the mouth of the tube to guide the fence post centrally of the tube.

9. The jack hammer of claim 7 wherein the handle secured to the driving ram is H-shaped with hand grips at the tops and bottoms of the vertical legs of the handle. 

1. A jack hammer comprising telescoped ram and guide barrel members, said barrel member slidably guiding said ram member for reciprocal movement along an elongated stroke, a driver head at one end of the barrel member having an impact surface, said ram member having a cooperatIng impact surface centered by the barrel member to engage said driver head impact surface, said impact surfaces of the ram member and driver head being interior of the telescoped ram and barrel members, an operating handle attached to the ram member adapted to be manually grasped for raising and lowering the ram member relative to the barrel member, and a recoil spring between the members effective to raise the ram member relative to the barrel member after each impact of the respective impact surfaces of the ram and barrel members, said spring having a free extended length substantially less than the stroke of the ram on the barrel to be compressed only at the bottom of the stroke before impact.
 2. The jack hammer of claim 1 wherein the ram is telescoped through the open top of the barrel.
 3. The jack hammer of claim 1 wherein the ram member is telescoped over the barrel member and the barrel member is hollow with an open bottom, has an anvil head at the top end thereof and receives the workpiece against said head.
 4. The jack hammer of claim 1 wherein the operating handle is H-shaped having a crossbar secured to the ram.
 5. The jack hammer of claim 1 wherein the barrel has a driving head secured on the bottom thereof.
 6. The jack hammer of claim 1 wherein the ram member is a hollow open bottom tube, receives the guide barrel therein in sliding relation therewith along the length thereof and has a driving head secured to the top thereof.
 7. A jack hammer which comprises a hollow open bottom guide tube having an anvil secured thereon closing the top end thereof, said guide tube being of larger diameter than a workpiece to be operated by said jack hammer for receiving the workpiece therein along the length thereof with anvil resting on the top end of the workpiece, a hollow elongated driving ram telescoped over said tube in sliding engagement therewith having a driving head adapted to impact against said anvil on the tube, a compression recoil spring in the hollow driving ram between the anvil and the driving head, said recoil spring having a free end and a free extended length substantially less than the stroke of the driving ram on the guide tube so as to be compressed only at the bottom of the stroke before the driving head impacts against the anvil and then becoming effective to raise the head away from the anvil, a handle secured to the driving ram and projecting laterally therefrom to be grasped by an operator in spaced relation from said ram for raising and lowering the ram to impact the head thereof against the anvil to transfer a blow to the workpiece on which the anvil rests.
 8. The jack hammer of claim 7 wherein the hollow guide tube receives a fence post therein and a guide member is provided in the mouth of the tube to guide the fence post centrally of the tube.
 9. The jack hammer of claim 7 wherein the handle secured to the driving ram is H-shaped with hand grips at the tops and bottoms of the vertical legs of the handle. 